S134-E-007289 (18 May 2011) --- NASA astronaut Greg Chamitoff, STS-134 mission specialist, prepares to open the hatch that will lead the space shuttle Endeavour crew into the International Space Station. The two spacecraft docked at 6:14 a.m. (EDT) and the Endeavour crew entered the orbital outpost at 7:38 a.m. May 18, 2011. Photo credit: NASA